Monoterpene table

Conifers tend to be sources of a variety of larger terpenoids, a major component of which are the Cl(l monoterpenes (Table 6.24). The structures of some of these are shown in Fig. 6.22. The mechanisms of the formation of these hydrocarbons in plants are closely linked, so that emissions of more than one monoter-pene often occur together. For example, geranyl... 

Table 2. Properties of Selected Monoterpene Hydrocarbons and Ethers...

Table 2.3 Levels of selected compounds and total monoterpenes, sesquiterpenes, and triketones from Leptospermum scoparium (from Perry et al., 1997a)...

Included in the table are data for L. scoparium obtained from five sites in Australia. The Australian material exhibited a level of a-pinene approaching that of the northern race from New Zealand, but was clearly characterized by the highest level of 1,8-cineole observed in the study, along with the highest value for total monoterpenes and lowest value for total sesquiterpenes. The authors noted the need for further taxonomic study, particularly of the Australian material. 

Table 3.1 Concentrations of selected monoterpenes from populations of Pinus albicaulis (from Zavarin et al., 1991)...

Table 5.3 Distribution of halogenated monoterpenes in Plocamium hamatum from the Great Barrier Reef (from Konig et al., 1999)...

Table 5.4 Occurrence of acyclic and cyclic polyhalogenated monoterpenes in Plocamium cartilagineum...

Table 5.5 Variation in selected halogenated monoterpenes in Plocamium cartilagineum coUected from sites in Chile (from San-Martin and Rovirosa, 1986)...

Table 9.2 Incorporation rate of [2-14C]-pyruvate into monoterpenes of isolated peppermint oil gland secretory cells in the presence of fosmidomycin, a specific inhibitor of 1-deoxy-D-xylulose 5-phosphate reductoisomerase, an enzyme of the mevalonate-independent pathway of isoprenoid biosynthesis.

TABLE 3-14 Photoxidation and Ozonolysis Rates of Monoterpene Hydrocarbons"... 

A lot of published data on the separation of enantiomers of flavors and fragrances by GC is reviewed by Chirbase/Flavor database. Table 1. summarizes the enantiomer separation of oxygenated monoterpenes on chiral stationary phases of cyclodextrin derivatives by high resolution gas chromatography. 

Table 1. Enantiomer Separation of Oxygenated Monoterpenes on Chiral Stationary Phases of Cyclodextrin Derivatives by High Resolution Gas Chromatography...

Table 1 includes many but not all, chiral stationary phases used to separate the oxygenated monoterpenes. 

The Lauraceae is a family from which relatively few isoprenylated chalcones have been reported, and only one new example, linderol A (40), from the bark of Linder a umbellata, is listed in Table 16.2. In this compound, the B-ring is unsubstituted (Figure 16.7), a common feature of Lauraceae chalcones. Several other unusual monoterpene-substituted chalcones have been reported previously from the Lauraceae genera Aniba and Lindera. The unusual structure of linderol A (40), in which the A-ring is functionalized by a cyclized monoterpenyl substituent, prompted the first total synthesis of this molecule. 

Table 6.24, for example, shows one estimate of the annual global emissions of isoprene, other monoterpenes, and VOCs as well as methane (Guenther, 1999). Emissions of isoprene are believed to be about four times those of the other monoterpenes and about equal to all other VOCs. 

Table VII shows the Increase In cytochrome P-450 content In mlcrosomes from southern armyworm larval midguts resulting from dietary exposure to several cyclic monoterpenes ( ). It also shows a closely corresponding Increase In the rate of NADPH oxidation when pyrethrum Is the substrate (R) being oxidised. The microsomal cytochrome P-450 system Is arranged as outlined In Figure 6, consisting of a terminal heme-lron protein that In the oxidised (Fe3+) state binds the substrate (R). The complex undergoes two reductions during which bound molecular oxygen Is converted to free radical species, one of which Is Inserted In the substrate molecule, and the other one forms water. The reductions...

Important aroma compounds of black currant berries have been identified mainly by GC-O techniques by Latrasse et al. [119], Mikkelsen and Poll [115] and Varming et al. [7] and those of black currant nectar and juice by Iversen et al. [113]. The most important volatile compounds for black currant berry and juice aroma include esters such as 2-methylbutyl acetate, methyl butanoate, ethyl butanoate and ethyl hexanoate with fruity and sweet notes, nonanal, /I-damascenone and several monoterpenes (a-pinene, 1,8-cineole, linalool, ter-pinen-4-ol and a-terpineol) as well as aliphatic ketones (e.g. l-octen-3-one) and sulfur compounds such as 4-methoxy-2-methyl-butanethiol (Table 7.3, Figs. 7.3, 7.4, 7.6). 4-Methoxy-2-methylbutanethiol has a characteristic catty note and is very important to blackcurrant flavour [119]. 

The root of carrot Daucus carota) is eaten raw or cooked. The characteristic aroma and flavour of carrots are mainly due to volatile compounds, although non-volatile polyacetylenes and isocoumarins contribute significantly to the bitterness of carrots [1,2]. More than 90 volatile compounds have been identified from carrots (Table 7.9) [207-215]. The carrot volatiles consist mainly of terpenoids in terms of numbers and amounts and include monoterpenes, sesquiterpenes and irregular terpenes. Monoterpenes and sesquiterpenes account... 

Table 17.3 Monoterpene compounds from Melaleuca and Eucalyptus species [45]...

A number of plants produce a variety of monoterpenes. The following table lists just a few of these sources, and their major monoterpene components. 

Structures and 13C chemical shifts (in ppm) of selected bicyclic monoterpenes are collected in Table 5.4. 

By AEDA the four odorants shown in Figure 9 were detected with the highest FD-factors in dill herb [33], A mixture of these compounds, dissolved in water at the same concentration ratios occurring in the herb (Table 16) very much resembled the typical odor of the dill herb. If (S)-a-phellandrene or the dill ether (B and A Fig. 9), respectively, were omitted, the mixture lost its typical odor note. On the contrary, omission of myristicin and methyl 3-methylbutanoate (D and C Fig. 9) did not significantly influence the overall dill herb aroma of the model mixture [33, 66], The data indicated that (S)-a-phellandrene and the dill ether are the character impact compounds of the dill herb. Since, on the basis of AEDA or calculation of OAVs further odorants have been shown to contribute to the dill herb flavor [33, 66], the results of the simulation experiments revealed that obviously the two monoterpenes are able to mask the flavor contributions of these compounds. 

---